Final answer:
The most useful radiometric clocks used in geologic studies are the option b. Uranium-Neodymium (U-Nd) Clock, the Monazite-Baddeleyite (M-B) Clock, and the Potassium-Argon (K-Ar) Clock, which are used to determine the age of rocks.
The correct option is B. Uranium-Neodymium (U-Nd) Clock
Step-by-step explanation:
The most useful radiometric clocks used in geologic studies are the Uranium-Neodymium (U-Nd) Clock, the Monazite-Baddeleyite (M-B) Clock, and the Potassium-Argon (K-Ar) Clock.
The U-Nd Clock is used to determine the age of rocks by measuring the ratio of uranium-238 to lead-206. The M-B Clock is used to date rocks by analyzing the ratio of certain isotopes of monazite and baddeleyite minerals. The K-Ar Clock is used to date rocks by measuring the ratio of potassium-40 to argon-40.
These radiometric clocks are important tools in geology because they provide scientists with valuable information about the age of rocks and the Earth's history.